How to call variables and methods of parent class in php subclass

[php]  view plain  copy

1. <?php  
2.   
3. class A{  
4.     public$a1='a1';   
5.     protected$a2='a2';   
6.     function test(){  
7.            echo"hello!<hr/>";   
8.     }  
9. }  
10. class  B  extends  A{ //If class A and class B are not in the same file, please include and then operate  
11.     public$a1='b1';   
12.     function test2(){  
13.             $this->test();  
14.               parent::test(); //Subclass calls parent class method  
15.     }  
16.     function test()  
17.     {     
18.         echo$this->a1.',';   
19.         echo$this->a2.',';   
20.         echo"b2_test_hello<hr/>";   
21.     }  
22. }  
23. $a = new B();  
24. $a->test();//b1,a2,b2_test_hello  
25. $a->test2();//b1,a2,b2_test_hello//hello!  
26.   
27. ?>
    

Method call: $this->method name(); If there is this method in the subclass, the method in the subclass is called, if not, the

          parent:: in the parent class is called, and the method in the parent class is always called Methods.

Variable call: $this->variable name; if there is this variable in the subclass, it will be called in the subclass, if not, it will be called in the parent class